LANDOVER, Md. -- The Minnesota Vikings didn't blitz Robert Griffin III much on Sunday. The electric rookie quarterback reminded them why in the fourth quarter.

The Washington Redskins' lead had gone from 19 points to five with 2 minutes, 56 seconds to go when Vikings defensive coordinator Alan Williams dialed up a six-man pressure they hadn't shown all day.

Linebacker Chad Greenway and Jasper Brinkley lined up in the "A" gaps and rushed on the snap. But halfback Ryan Grant cut Brinkley, Greenway got tied up with center Will Montgomery and Griffin burst through the resulting hole for a 76-yard touchdown that all but sealed the Redskins' 38-26 victory.

"We were very concerned about it going into the ballgame," Vikings coach Leslie Frazier said. "We wanted to pick our spots when we did (blitz). We knew what the potential ramifications would be if we did do it and didn't get there."

Replays appeared to show Greenway getting held as Griffin sped past, but he said he wasn't sure if a flag should have been thrown.

"It's tough," Greenway said. "With a guy who's athletic like that, you've just got to make the call and play ball. It's easy to sit here and second-guess all the calls. ... That's why you play the game. Obviously, it's reaction. You play the call and go and he made a play with his feet and it ended up hurting you."

Making matters worse was the fact cornerback Chris Cook never saw Griffin break the pocket because he was focused on covering Joshua Morgan man-to-man. That allowed Griffin to steer around safety Jamarca Sanford to the sideline, where safety Harrison Smith dived and couldn't clip his heels around the Vikings' 40-yard line.

"We practiced what he did all week," Cook said. "All I can say is they out-executed us."

The touchdown run was the longest by an NFL quarterback since Kordell Stewart went 80 yards for the Pittsburgh Steelers against the Carolina Panthers in 1996.

It capped a highly productive day for Griffin, who had been listed as questionable on the injury report with the concussion he suffered one week earlier on a hit by Atlanta linebacker Sean Weatherspoon. He reportedly apologized to teammates earlier in the week for putting himself in harm's way.

"I saw the blitz," Griffin said, "and I was thinking I'm either going to throw hot, or if they miss this blitz and don't hit it the right way, I'm going to run for the first.

"I saw that they missed it, took off running and got to the sideline. Thought about running out of bounds, because everyone has been telling me that lately. ... I felt like I had the guy out-flanked, and I just took off running. The rest is history."

Griffin did make one big error, throwing an interception to cornerback Antoine Winfield that helped the Vikings built a 9-0 lead after one quarter.

Over the final 45 minutes, Griffin was 14-of-17 passing (82.4%) for 144 yards and a touchdown, plus 131 rushing yards and two scores on 12 carries. At several points, the crowd of 78,476 chanted "RG3!" in unison.

"We tried to contain him for most of the game," defensive tackle Kevin Williams said. "Then they picked up our blitz and he got out. He's a fast kid and he can run. He definitely showed his wheels."